Dishwasher



Aug. 1, 1967 F, E. LA FLAME DISHWASHER Filed Deo. P 1965 INVENTOR. @ank[afyame United States Patent O 3,333,742 DISHWASHER Frank E. La Flame,Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., acorporation of Delaware Filed Dec. 2, 1965, Ser. No. 511,043 1 Claim.(Cl. 222-333) ABSTRACT OF THE DISCLOSURE In preferred form, a dishwasherpump assembly located in the lower sump `of a washing compartment andincluding a drain pump and a primary circulation pump and wherein thepump impeller is secured to a shaft assembly including an invertedtubular fluid seal component that seals a shaft directed upwardly andinteriorly of the sump.

This invention is directed to an improved dishwasher assembly and moreparticularly to an improved plural pump assembly for draining fluid fromthe washing compartment of a dishwasher and for distributing washing uidthrough said washing compartment.

In many dishwasher assemblies a plural pump fluid distributingarrangement is included that is driven by a single motor to selectivelydrain fluid from the dishwasher and to distribute washing fluid in thewashing compartment thereof for removing soil from articles supported inthe washing compartment. In the past, rather elaborate motor mountingarrangements have been provided that are characterized Iby relativelyexpensive bearing arrangements for supporting the shaft of the singledrive motor with respect to driven irnpellers in the plural pumpassembly and elaborate seal arrangements to prevent fluid leakage alongthe shaft from within the washing compartment of the dishwasher.

An object of the present invention, therefore, is to improve dishwashingvapparatus of the type including a Was-hing compartment having a lowersump region in which drain pump means are provided to drain fluid fromthe dishwashing apparatus and fluid circulating pump means are providedto distribute washing fluid in cleaning contact with articles supportedin the compartment by the provision of a low-cost, unitary bearingsupport that locates a single motor shaft in driving relationship withirnpellers in both the drain and primary wash circulation pumps whileeliminating the need for a shaft seal assembly to prevent leakage offluid from the washing compartment of the dishwasher.

A further object of the present invention is to improve dishwashingapparatus of the type including a washing compartment having a lowersump region with a bottom opening by the provision therein of closuremeans for sealing the bottom opening including a depending portion forsupporting the stator of a motor exteriorly of the sump region and anupwardly directed open-ended tubular portion extending within the sumpregion and having the uppermost end thereof located without the sumpregion and wherein bearing means are provided within the tubularextension to serve as the sole means for rotatably supporting a r-otorconnected drive shaft of the motor in driving relationship with pluralpump assemblies located within the sump region.

A still further object of the present invention is to providedishwashing assemblies of the type set forth in the preceding objectwherein said closure means includes means for forming a drain pumpchamber having an inlet opening thereto surrounding said tubularextension and wherein a pump casing surrounds an upward portion of saidtubular extension to form in cooperation therewith a primary washingfluid pumping chamber and wherein a single coupling is provided foroperatively connecting pump irnpellers in said drain pump chamber andsaid pump casing in driving relationship with the `drive shaft of thesingle motor.

A further object of the present invention is to provide a dishwasherassembly of the type set forth in the preceding object wherein improvedmeans are included Within the tubular extension for lubricating thebearing means therein and for preventing the escape of lubricantinteriorly of the sump region.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

FIGURE 1 is a view in elevation, partially broken away, of a dishwashingapparatus including the present invention; and

FIGURE 2 is an enlarged view in vertical section showing the improvedmotor mounting and sealing arrangement in the dishwasher of the presentinvention.

Referring now to FIGURE l, a dishwasher 10 is illustrated having anouter casing 12 and a downwardly pivoting front door 14 that providesaccess into a washing compartment 16 formed by a Water container 18having a bottom wall 20 formed downwardly at 22 to form a sump region 24in direct communication with the washing compartment 16. The downwardlyformed portion 22 of the bottom wall 20 has an opening 26 formed thereinwhich is sealed by a closure member 28 on which is supported a `drivemotor 30 for operating a 4drain pump 32 that periodically withdrawsfluid from the sump region 24 to be discharged through an exterior drain34. The motor 30 also is operatively associated with a primary washfluid circulating pump assembly 36 located within the sump region 24 fordischarging fluid from the sump region 24 through a fluid `distributingsystem 38 into washing contact with articles supported within thewashing compartment 16. The motor 30 is a reversible electrical motorthat is controlled selectively for reverse rotation by a dishwashingcycle controller 40.

Referring more particularly to FIGURE 2, the downwardly formed portion22 has a radially inwardly directed edge portion 42 thereof thatsupportingly receives an annular resilient sealing member 44 thatsealingly supportingly receives an annular flange portion 46 of theclosure member 28. The closure member 28 further includes a bottomportion 48 extending across the full planar extent of the opening 26 inwhich is for-med an integral wall member 50 that defines a drain pumpchamber 52 in the bottom 48 of the closure 28 which is closed by a coverplate S4 having an opening 56 therein that serves as an inlet to thedrain pumping chamber S2 from the sump region 24. 'Ihe bottom 48 isformed to have a passageway 58 therein that serves as the discharge fromthe drain pumping chamber 52 and a depending tubular portion 60 thatcommunicates with passageway 58 and is connected to one end of the drain43. Details of the fluid communication between passageway 58 and thepumping chamber 52 are more specifically set forth in my copendingapplication, Serial No. 341,209, filed Ian. 30, 1964, now Patent No.3,265,311, issued Aug. 9, 1966.

The closure member 28 further includes depending portions 62, one ofwhich is illustrated, on which are secured a stator block 64 of themotor 30 by suitable means such as screws 66. The stator block supportsa stator coil 68 which has a dust shield 70 located on the bottom endthereof including openings 72 therein for circulation of cooling airacross the coil 68. The shield 70 is held on the coil 68 by a ring 74 ofa suitable adhesive material. The stator coil 68 is operativelyassociated with a rotor 76 of the motor 30 which is secured to a lowerend 78 of a vertically disposed drive shaft 80 that is directed upwardlyfrom the rotor 76 interiorly of an openended, elongated, upwardlyextending tubular portion 82 of the closure member 28 forming thehousing of a unitary bearing and seal unit 83 for the motor drive shaft80. The tubular portion 82 includes a lower open end located closelyadjacent the bottom 48 of the closure 28 in which is supported a ballbearing assembly 84 for supporting the lower end 78 of the shaft 80 forrotation Within the closure member 28 and against axial -thrust of therotor 76. An upper portion 86 of the shaft 80 is rotatably supported bya bearing sleeve 88 formed integrally and interiorly of the upper end ofthe tubular portion 82.

Between the bearings 84 and 88, the tubular portion 82 of the closuremember 28 is spaced from the outer periphery of the shaft 80 to formaspace 90 therebetween in which is located a lubricant impregnated,porous member 92. The porous lubricant containing member 92 serves as areservoir for lubricant for the lower and upper bearings 84, 88. Theshaft 80 has an inwardly tapered portion 94 thereon immediately belowthe sleeve bearing 88 and a like inwardly tapered portion 96 locatedimmediately above the bearing 88. The tapered portion 96 cooperates withan annular felt oil bearing member 98 seated in the upper end of thetubular portion 82 to form a lubricant collecting chamber 100. Thelubricant collecting chamber 100 is communicated with the porouslubricated member 92 through a drain passageway 102 formed in thebearing 88. By virtue of the illustrated arrangement, the lubricantcontained in the porous member 92 continually lubricates the ballbearing assembly 84 and the surface of the sleeve bearing 88 and furtherslings any oil that tends to migrate to the upper end of the shaft 80exteriorly of the shaft to collect in the chamber 100 to be returnedthrough the passageway 102. Accordingly, there is no oil leakage intothe sump region 24 that might contaminate the washing chamber 16 of thedishwasher 10.

The tubular portion 82 of the improved seal and bearing arrangement ofthe present invention isolates the bearings 84, 88 from water containedin the sump region 24 since the upper end thereof is located above thewater level in sump region 24 during all phases of the dishwash ingoperation.

In the illustrated arrangement, an inverted elongated cup-shaped drivecoupling member 104 has the base thereof secured by suitable means,shown as a screw 106, to the'upper end of the drive shaft 80 and istelescoped downwardly about the upwardly directed tubular portion 82 sothat a radially outwardly directed ange 108 on the lowest end of member104 is located within the drain pumping chamber 52. The edge 108 carriesa plurality of blades 110 that, upon rotation of the motor 30 in apredetermined direction, will draw fluid from the sump region 24 throughthe inlet opening 56 and thence discharge it through the drainpassageway 58 into the drain conduit 34. The coupling member 104 islocated in close spaced relationship with the tubular portion 82 of theclosure member 28 to maintain a compact arrangement that utilizes aminimum of space in the sump region 24 whereby uid is relatively free toreturn from the Washing compartment 16 into the sump region 24, forexample, to be drained therefrom by the drain pump 32. An opening 111 inange 108 by-passes the pressure side of impeller blades 110 to thesuction side thereof to prevent uid ow into member 104.

A further characteristic of the improved motor shaft and seal assemblyis that it is readily adapted for association with low-cost,high-capacity primary fluid circulation pumps, for example, of the axialflow type. Thus, in the illustrated arrangement, the pump 36 is seen toinclude a tubular outer casing 112 that has an opening 114 in its lowerend in which is received a uid diverter element 116 of the type morespecifically set forth in my copending application, Ser. No. 341,209,now Patent No. 3,265,- 311, issued Aug. 9, 1966, referred tohereinbefore. This diverter directs uid from the sump region 24 into aninterior pumping chamber 118 of the tubular casing 112 where an axial owirnpeller 120 is located and secured to the outer surface of thecoupling member 104 intermediate the ends thereof for rotationtherewith. The rotating impeller 120 will displace fluid from pumpingchamber 118 upwardly through flow straightening vanes 122 in the tubularcasing 112 thence into .the interior of a rotary spray bar 124 (shown inbroken lines) that is secured for rotation with respect to the casing112 by a stud element 126 with a head fit into an interior surface of acentral hub 128 that extends upwardly from the upper end of the casing112 in surrounding relationship with the coupling member 104. The hub128 is spaced from the coupling member 104 to form an opening 130therebetween in communication with the pumping chamber 118. The couplingmember 104 serves as a seal against uid passing from the pumping chamber118 into the shaft bearing assembly.

The above-described dishwashing apparatus including the low-cost,compact, plural pump and single drive motor assembly therein ischaracterized by reliable operation with elimination of water leakagefrom the sump regions of dishwashing apparatus outwardly along a drivemotor shaft. The apparatus is also characterized in part by a lowcost,easily accessible unitary bearing and seal assembly that eliminates theneed for expensive rotary seal assemblies of the type previously foundin dishwashing apparatus with such two-pump assemblies. Furthermore, theunit is characterized by an improved lubricant arrangement that isself-contained within the bearing support for the single drive motorwhich prevents the ingress of lubricant into the interior of thedishwasher. A further advantage is that the bearing mount and sealarrangement in the plural pump and single drive combination is arrangedin an unusually compact fashion wherein it will not interfere with theuid flow patterns in the dishwashing apparatus during both drain andwash cycles of operation.

Furthermore, the plural pump and its included bearing and sealarrangement makes use of a single closure member to form a drain pumpingchamber, :a support for the stator of a motor without requiring an endmotor frame and a housing for a combined shaft bearing assembly andwater seal :assembly that is included in a single tubular portion on thesame closure member.

A further feature of the invention is that the combination includes asingle coupling member that includes plural impellers directly connectedthereto for providing a low-cost coupling between the drive shaft of amotor and pump assemblies of the type under discussion.

While the embodiment of the present invention as herein disclosedconstitutes -a preferred form, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

In a dishwasher assembly, the combination of, wall means forming awashing compartment including a sump region having a bottom opening,closure means for sealing said bottom opening including motor mountingmeans having a first portion supportingly -received by said wall means,a second portion depending from said wall means and an upwardly directedtubular extension with :a lower open end located closely adjacent saidsump region and an upper open end located within said washingcompartment above said sump region, ya motor having a rotor and astator, `means for securing said stator to said depending portion ofsaid closure means, ashaft .having one end thereof connected to saidrotor and directed interiorly of said tubular portion to locate theopposite end thereof at the upper open end of said tubular extension,thrust vbearing means in said lower open end of said tubular extensionfor supporting said shaft for rotation with respect to said tubularextension, second bearing means in said tubular extension below saidupper open end thereof for rotatably supporting said other end of saidshaft for rotation with respect to said tubular extension, means in saidclosure means for forming a drain pump chamber therein including meansfor forming an opening about said tubular extension communicating saiddrain pump chamber with said sump region, pump casing means surroundingsaid tubular portion above said drain pump chamber and Within said sumpregion and forming a primary uid pumping chamber, first impeller meanslocated in said drain pump chamber, second impeller means located insaid pump casing, an inverted tubular member telescoped over saidtubular portion including an upper end portion connected to said othershaft end and a lower portion secured to said rst impeller, said secondimpeller being secured to said inverted cup-shaped member intermediatethe ends thereof within said primary pumping chamber, means forcommunicating said primary pumping chamber with said sump region andWith said Washing compartment and means for communicating said drainpump chamber with an exterior drain, said inverted elongated cup-shapedmember serving to direct power from said motor shaft to said rst andsecond impellers and cooperating with said tubular extension of saidclosure member to prevent fluid leakage eXteriorly of said sump regionalong said shaft.

References Cited UNITED STATES PATENTS 2,023,107 12/1935 Stoddard134-182 3,126,025 3/1964 Aubert et al 134-186 ROBERT B. REEVES, PrimaryExaminer.

STANLEY H. TOLLBERG, Examiner.

